Mobile terminals with touchscreens, for example, mobile phones or tablet computers facilitate operations of people and are trending towards big screens. However, in some application scenarios, for example, when a user is on a bus or when a user is walking, two hands cannot conveniently operate a mobile terminal. In addition, because a screen is relatively large, the entire screen is not within the reach of a single hand during an operation.
Currently, a touch-control function may be added to a frame of a mobile terminal, to control scaling of a display area of a screen. However, scaling can be performed only on an image on a display area of a screen, a particular size can be obtained by means of scaling only at a fixed proportion, and a display area obtained by means of scaling cannot be within the reach of single hands of all users.